Error estimation for the MAP experiment

We report here the first full sky component separation and CMB power spectr um estimation using a Wiener filtering technique on simulated data from the upcoming MAP experiment, set to launch in early 2001. The simulations incl uded contributions from the three dominant astrophysical components expecte d in the five MAP spectral bands, namely CMB radiation, Galactic dust, and synchrotron emission. We assumed a simple homogeneous and isotropic white n oise model and performed our analysis up to a spherical harmonic multipole l(max) = 512 on the fraction of the sky defined by \b\ > 20 degrees. We fin d that the reconstruction errors are reasonably well fitted by a Gaussian w ith an rms of 24 muK, but with significant deviations in the tails. Our res ults further support the predictions on the resulting CMB power spectrum of a previous estimate by Bouchet & Gispert (1999), which entailed a number o f assumptions this work removes.